@misc{VesteLittmannKunnekeetal., author = {Veste, Maik and Littmann, Thomas and Kunneke, Anton and Du Toit, Ben and Seifert, Thomas}, title = {Windbreaks as part of climate-smart landscapes reduce evapotranspiration in vineyards, Western Cape Province, South Africa}, series = {Plant, Soil and Environment}, volume = {66}, journal = {Plant, Soil and Environment}, number = {3}, issn = {1214-1178}, doi = {10.17221/616/2019-PSE}, pages = {119 -- 127}, abstract = {Under the conditions of climate change in South Africa, ecological and technical measures are needed to reduce the water consumption of irrigated crops. Windbreak hedges are long-rated systems in agriculture that significantly reduce wind speed. Their possibilities to reduce evapotranspiration and water demand are being investigated at a vineyard in the Western Cape Province, South Africa. Detailed measurements of meteorological parameters relevant for the computation of reference and crop-specific evapotranspiration following the FAO 56 approaches within a vineyard in the Western Cape Province of South Africa have shown the beneficial effect of an existing hedgerow consisting of 6 m high poplars (Populus simonii (Carri{\`e}re) Wesm.). With reference to a control station in the open field, the mean wind speed in a position about 18 m from the hedgerow at canopy level (2 m) was reduced by 27.6\% over the entire year and by 39.2\% over the summer growing season. This effect leads to a parallel reduction of reference evapotranspiration of 15.5\% during the whole year and of 18.4\% over the growing season. When applying empirical crop-specific Kc values for well-irrigated grapes, the reduction of evapotranspiration is 18.8\% over the summer growth period. The introduced tree shelterbelts are a suitable eco-engineering approach to reduce water consumption and to enhance water saving in vineyards.}, language = {en} } @misc{FischerKholiavkoSchaafetal., author = {Fischer, Thomas and Kholiavko, Tatiana and Schaaf, Wolfgang and Veste, Maik}, title = {Soil respiration responses of moss and lichen biocoenoses to moderate and severe rain events after summer drought in a temperate early-successional ecosystem}, series = {Ecohydrology}, volume = {16}, journal = {Ecohydrology}, number = {7}, issn = {1936-0592}, doi = {10.1002/eco.2578}, abstract = {It is commonly accepted that CO2 efflux increases with soil water content in aerated soils and that rewetting after periods of soil drying can result in respiration pulses. It has further been shown that soil pores may become water logged which can impede soil gas exchange. The present study aimed to quantify the carbon response of moss (Polytrichum piliferum) and lichen (Cladonia coniocraea) biocoenoses to different quantities of rain in an artificial catchment, which granted that the starting point of the development of both biocoenoses was the same. To address this aim, we conducted in situ soil moisture and soil respiration measurements, where soil respiration was hypothesised to emerge from a cryptogamic vegetation layer and from mineral soil beneath. We found that higher water-holding capacity of the moss layer and higher accumulation of organic matter in the upper mineral soil under mosses result in higher amounts of water stored near the surface. As a consequence, evaporation of water as well as pulses of CO2 efflux after moderate rain following a period of drought were higher in the moss biocoenosis, where the upper mineral soil was of key importance. In contrast, the lichen biocoenosis facilitated penetration of rainwater into the deep soil. Superimposing rewetting pulses, near-saturation of soil pores with water after severe rain resulted in gas exchange inhibition and diminished soil respiration until subsequent aeration in both biocoenoses}, language = {en} } @misc{GeldenhuysLoetzeVeste, author = {Geldenhuys, Heinrich and L{\"o}tze, Elmi and Veste, Maik}, title = {Fruit Quality and Yield of Mandarin (Citrus reticulata) in Orchards with Different Windbreaks in the Western Cape, South Africa}, series = {Erwerbs-Obstbau}, volume = {65 (2023)}, journal = {Erwerbs-Obstbau}, number = {4}, issn = {1439-0302}, doi = {10.1007/s10341-022-00725-3}, pages = {959 -- 969}, abstract = {Windbreaks, trees, structures, and shade nets are used in South Africa to protect citrus orchards from wind scar damage to avoid major losses in export quality. Severe southeasterly winds in the Western Cape during spring and summer are the main causes of significant external peel damage. In this study, wind scar damage of 'Tango' mandarin (Citrus reticulata) fruit was quantified at different distances from established Casuarina cunninghamiana (Beefwood) and Populus simonii (Chinese Poplar) windbreaks around Stellenbosch, Western Cape, South Africa. The yield efficiency was not significantly affected by distance from the windbreak in either of the trials. Fruit at 2 H and 3 H had significantly lower ratios of total soluble solids to titratable acidity, but export standards for mandarins were still met. The wind speed was consistently higher at 16 H, compared with 3 H during summer. The highest packout (class 1 fruit) was observed near the windbreak (3 H) and decreased as the distance increased towards 10 H and 16 H. There were no significant differences for severe wind scar damage incidence between the distance treatments. Our results confirmed the impact of wind on external fruit quality and the limitation of tree-based windbreaks with an increase in distance, which partly supports the current movement towards full enclosure of orchards with shade nets.}, language = {en} } @misc{VesteHalkeGarbeetal., author = {Veste, Maik and Halke, Christian and Garbe, Daniel and Freese, Dirk}, title = {Einfluss von Stickstoffd{\"u}ngung und Kompost auf Photosynthese und Wachstum der Virginiamalve (Sida hermaphrodita Rusby)}, series = {Journal f{\"u}r Kulturpflanzen}, volume = {68}, journal = {Journal f{\"u}r Kulturpflanzen}, number = {12}, issn = {1867-0911}, doi = {10.1399/JFK.2016.12.13}, pages = {423 -- 428}, abstract = {Als mehrj{\"a}hrige Bioenergiepflanze kann Sida hermaphrodita eine wichtige Rolle f{\"u}r den Anbau auf marginalen Standorten in der nahen Zukunft spielen. In einem kontrollierten Topfexperiment wurde der Einfluss von verschiedenen Kompostgehalten (10, 20, 30, 50\%) und mineralischem Stickstoffd{\"u}nger (100 kg N ha-1) auf Biomasse, Wuchsh{\"o}he und Kohlenstoffallokation w{\"a}hrend der Etablierungsphase untersucht. Weiterhin wurden {\"o}kophysiologische Parameter (Gaswechsel, Chlorophyllfluoreszenz, Chlorophyllgehalte) mit nicht-destruktiven Methoden bestimmt. Die Ergebnisse des Experimentes zeigen, dass sowohl die Stickstoffd{\"u}ngung als auch die Kompostgabe positive Effekte f{\"u}r das Wachstumsverhalten hat. W{\"a}hrend der Etablierungsphase erreichten die ged{\"u}ngten Pflanzen eine mittlere Pflanzenh{\"o}he von bis zu 127 cm (maximale Wuchsh{\"o}he 168 cm). Die Photosynthese wurde nicht durch die unterschiedlichen Behandlungen beeinflusst. Die mittlere CO2-Austauschrate variiert zwischen 5,8 und 9,9 μmol m-2 s-1 und die Elektronentransportrate zwischen 34,5 und 53,9 μmol m-2 s-1. Die Verwendung von Kompost und Stickstoff ist f{\"u}r eine bessere Biomasseproduktion von Sida in marginalen B{\"o}den m{\"o}glich, auch wenn das Wachstum im ersten Jahr limitiert ist und es negative R{\"u}ckwirkungen auf die Bestandesetablierung gibt.}, language = {de} } @misc{KidronVesteLichner, author = {Kidron, Giora J. and Veste, Maik and Lichner, Lubomir}, title = {Biological factors impacting hydrological processes: Pecularities of plants and biological soil crusts}, series = {Journal of Hydrology and Hydromechanics}, volume = {69}, journal = {Journal of Hydrology and Hydromechanics}, number = {4}, issn = {1338-4333}, doi = {10.2478/johh-2021-0031}, pages = {357 -- 359}, abstract = {The effects of biological factors on the water cycle and subsequently on hydrological processes have wide and profound consequences on ecosystem structure, function and management. A profound understanding of their effects is of prime importance especially in light of climate change projection}, language = {en} } @misc{KueppersKueppersHornaetal., author = {K{\"u}ppers, Manfred and K{\"u}ppers, Barbara I. L. and Horna, Viviana and Veste, Maik and Zimmermann, Reiner and Lauerer, Marianne and Aas, Gregor}, title = {Green barks of trees from drought deciduous forests ("bosque seco") in northern Peru/southern Ecuador do not perform CAM}, series = {Basic and Applied Dryland research}, journal = {Basic and Applied Dryland research}, issn = {1864-3191}, doi = {10.1127/badr/2015/0002}, pages = {15}, abstract = {Trees from drought deciduous forests ("bosque seco") in northern Peru and southern Ecuador regularly shed their leaves at the onset of seven months-long periods without rain. This way they very effectively reduce the bulk water consumption by leaf transpiration, still loosing small amounts of water through their bark, but at the risk of too little or no carbon gain when leaf-less. Seven species studied here have good developed green cortex tissue on stems and axes, as especially evident for the "bottle tree" Ceiba trischistandra (A. Gray) Bakhuisen (Bombacaceae). In several leaf-less tree species at the end of summer drought, when xylem sap flows are very low, indications of higher xylem flows at night as compared to day-time were found, which led to the question of whether the trees are capable of performing CAM in their axes. However, although quite low in some cases, the pH of the cortex tissues did not fluctuate diurnally. In addition, no night-time carbon uptake could be observed. Although no net carbon gain was measured in C. trischistandra and Erythrina smithiana Krukoff (Fabaceae) photosynthetic activity of the green cortex was sufficient to re-assimilate between 50\% to 60\% of the carbon released by mitochondrial respiration. In contrast, the obligate CAM plant Cereus diffusus (Britton \& Rose) Werdermann (Cactaceae), which was studied as a reference in the same environment, showed both diurnal pH-fluctuations in its green tissue with lowest values before sun rise, and net carbon fixation at night.}, language = {en} } @misc{Veste, author = {Veste, Maik}, title = {Biologische Bodenkrusten - Pioniere der B{\"o}den}, series = {Naturmagazin Berlin - Brandenburg}, volume = {36}, journal = {Naturmagazin Berlin - Brandenburg}, number = {1}, issn = {0935-7602}, pages = {14 -- 15}, abstract = {Nach extremen St{\"o}rungen durch Br{\"a}nde, Vulkanausbr{\"u}chen und Hangrutschungen, aber auch menschlichen Eingriffen werden B{\"o}den mehr oder weniger zerst{\"o}rt und vegetationsarm. Es entstehen sogenannte initiale Rohb{\"o}den, die durch Ver{\"a}nderung der Bodenstruktur, Minderung der Wasserhaltekapazit{\"a}t als auch durch N{\"a}hrstoffarmut extrem beeinflusst werden. Dabei haben anf{\"a}ngliche und n{\"a}hrstoffarme {\"O}kosysteme, wie Grasl{\"a}nder und Offenlandschaften, aus Sicht des Naturschutzes einen hohen Wert f{\"u}r die Landschaft und sind in der intensiv genutzten Kulturlandschaft Mitteleuropas selten geworden. Insbesondere bieten Binnend{\"u}nen, wie sie in Norddeutschland h{\"a}ufig sind, Potenzial f{\"u}r die Entwicklung von initialen Lebensr{\"a}umen mit ihren spezifisch angepassten Pflanzen. Neben den Pionierarten werden die Rohb{\"o}den, wie sie nach St{\"o}rungen entstehen, zuerst durch verschiedene bl{\"u}tenlose Pflanzen, den sogenannten Kryptogamen, besiedelt.}, language = {de} } @misc{LebzienVesteFechneretal., author = {Lebzien, Stefan and Veste, Maik and Fechner, H. and Koning, Laurie Anne and Mantovani, Dario and Freese, Dirk}, title = {The Giant Knotweed (Fallopia sachalinensis var. Igniscum) as a new plant resource for biomass production for bioenergy}, series = {EGU General Assembly 2012, held 22-27 April, 2012 in Vienna, Austria}, journal = {EGU General Assembly 2012, held 22-27 April, 2012 in Vienna, Austria}, publisher = {European Geophysical Society}, address = {Kattenburg-Lindau}, pages = {1}, language = {en} } @misc{MaWeberRaggioQuilezetal., author = {Ma, Yunyao and Weber, Bettina and Raggio Qu{\´i}lez, Jos{\´e} and Colesie, Claudia and Veste, Maik and Bader, Maaike Y. and Porada, Philipp}, title = {Determining key drivers of the annual carbon budget of biocrusts in different climatic zones}, series = {EGU General Assembly 2022, Vienna, Austria \& Online | 23-27 May 2022}, journal = {EGU General Assembly 2022, Vienna, Austria \& Online | 23-27 May 2022}, doi = {10.5194/egusphere-egu22-3714}, abstract = {Biocrusts are distributed over all climate zones of the world and they substantially contribute to ecosystem functioning. Their growth, determined by their carbon balance, can be affected by various climatic drivers. The effects of individual drivers are clear from laboratory experiments, but the relative importance of different drivers along climatic gradients and their underlying mechanisms are largely unknown. Moreover, the effects of seasonal acclimation on the annual carbon balance are not fully understood either. Therefore, we aim at determining the level and variation of annual biocrust carbon balances and their connection to climatic drivers along environmental gradients. In addition, we explore the role that acclimation plays in the carbon balance of biocrusts}, language = {en} } @misc{VesteGreyGottschalketal., author = {Veste, Maik and Grey, Kerry-Anne and Gottschalk, Nadine and Trachte, Katja and Midgley, Guy F.}, title = {Can shelterbelt trees reduce evapotranspiration and ecophysiological stress in irrigated vineyards and citrus orchards? A transcontinental experiment in the Western Cape, South Africa and Lower Lusatia, Germany}, series = {Landscape 2021 - Diversity for Sustainable and Resilient Agriculture}, journal = {Landscape 2021 - Diversity for Sustainable and Resilient Agriculture}, doi = {10.13140/RG.2.2.34333.03043}, pages = {1}, abstract = {In the context of ongoing climate change and increasing population, there is an urgent need to optimize the water consumption of surface and groundwater in agricultural production. In recent years, intensive irrigated viticulture and horticulture have faced increasing demand pressure in many water-limited areas including the Western Cape Province in South Africa. Shelterbelts of trees are often used to reduce wind speed and water demands as an eco-engineering measure directly influencing soil evaporation and crop transpiration. Objectives are (i) to evaluate the extent of impacts of wind speed from shelterbelts at canopy level in citrus orchards and vineyards (ii) to assess the wind effects at leaf level including leaf temperature and related ecophysiological performance in irrigated vineyards.}, language = {en} }